JPS6019346B2 - Thermosetting encapsulation material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting sealing material, which is used for sealing and closing gaps or corners with a thermosetting resin by utilizing the fluidity of the resin when it is heated. It is something that

As is well known, when a pin inserted through a plate is sealed and fixed at the opening of its insertion hole, a two-component epoxy adhesive is often used.

Sealing and fixing with this two-component epoxy adhesive is carried out by mixing the base agent and a softener at the time of use, applying this to the predetermined sealing area, and then heating and curing it in a hot air oven. be done. However, this method has problems such as adhesion of adhesive to unnecessary areas and difficulty in uniform application, restrictions on pot life after application, and variations in application conditions (e.g.
The sealing effect is also affected by variations in the time from mixing the two liquids until application.

In particular, when the viscosity of the adhesive is adjusted using a solvent, there is a problem that the resin material foams during drying and curing in a hot air oven, which significantly impairs the sealing effect. By the way, the applicant of the present application has developed an insulating tape or sheet for heat-resistant electrical equipment, which is composed of successive layers of a thermosetting resin layer, a heat-melting type contact prevention film layer, and a hardening agent layer. A fiber base material is embedded in at least one of the curing agent layers, and the heat-melting contact prevention film layer is a composite material having approximately the same melting temperature as the other two layers or a slightly lower melting temperature. We have already proposed sheet materials.

In this composite sheet, since contact between the thermosetting resin layer and the curing agent layer is normally prevented by the heat-melting contact prevention film, the curing reaction is not promoted.

On the other hand, when heated, the hot-melt contact prevention film layer melts, and further the thermosetting resin layer and the curing agent layer are melted and mixed to start curing. This curable composite sheet material is
It is non-adhesive and easy to handle without the stickiness of liquid materials. Further, since there is no need for a coating operation in the case of a liquid material, and it is sufficient to simply attach the sheet body to a predetermined location, various inconveniences associated with the application of a liquid material are automatically eliminated. However, the above-mentioned composite sheet material has been developed as an electrically insulating sheet or tape, and as it is, it is impossible to use it as the above-mentioned sealing material.

That is, the above-mentioned sealing material is required to have appropriate softening fluidity, but the above-mentioned electrically insulating composite sheet material lacks this point. In particular, the fiber base material embedded in the composite sheet material is used to impart mechanical strength to the insulator after curing, and is required to function as a skeleton. Therefore, it is necessary to use a material that at least retains its shape at the temperature during the curing reaction. For example, inorganic fiber cloth such as glass fiber or asbestos fiber, or heat-resistant synthetic fiber cloth such as polyester fiber is used. There is. These fibrous base materials inhibit the softening fluidity required for the above-described sealing. Of course, the fiber base material of the composite sheet material is selected in relation to the curing reaction temperature of the thermosetting resin layer and curing agent layer, and when the curing reaction temperature is low, fibers with a relatively low melting point are selected. It is also possible to use substrates, for example synthetic fabrics such as polypropylene fibres. However, even in this case, since the synthetic fiber cloth such as polypropylene fiber is the above-mentioned mechanically reinforcing skeleton material, the softening fluidity required for the above-mentioned sealing cannot be achieved. The thermosetting sealing material according to the present invention provides a thermosetting composite sheet material suitable for heat-melting sealing, and includes a thermosetting resin layer, a curing agent layer, and a thermosetting resin layer. It consists of a heat-melting type contact prevention film layer interposed between the curing agent layer, and a thermoplastic resin fiber base material or film is present in at least one of the thermosetting resin layer and the curing agent layer. The substrate or film and the hot-melt contact prevention film layer are characterized by having substantially the same softening point or melting temperature as the other two layers, or a lower softening point or melting temperature.

In the thermosetting sealing material configured in this way, the thermosetting resin layer and the curing agent layer are separated by the heat-melting contact prevention layer at room temperature, so curing is not promoted.

When heated, the hot-melt contact prevention film layer is melted,
While the thermosetting resin layer and the curing agent layer are melt-mixed,
The thermoplastic fiber base material or film is also softened or melted, and with good resin flow, the molten mixture spreads over the area to be sealed and is finally hardened. As described above, according to the sealant of the present invention, reliable sealing can be achieved without the various problems that occur when using a liquid curable sealant.

Thermosetting resins used in the present invention include epoxy resins, polyester resins, silicone resins, and phenol resins.

The curing agent used in the present invention may be any highly reactive curing agent that cures the corresponding thermosetting resin.

For example, curing agents for epoxy resins include imidazoline, imidazole, and polyamide resins as coreactive resins, and curing agents for polyester resins include penzoyl peroxide, dicumyl peroxide, and silicone. Curing agents compatible with resins include trietanoamine, imidazole, etc., and curing agents compatible with phenolic resins include hexamethylenetetramine, valatoluenesulfonic acid, etc. As the heat-melting type contact prevention film layer, one is used that has the same or slightly lower melting temperature as the thermosetting resin layer and the curing agent layer, and has good compatibility with both. .

For example, polyethylene, polyvinyl chloride, polyethylene oxide, polyacrylic ester, and ethylene monovinyl acetate copolymer are selected depending on the thermosetting resin, the material of the curing agent, and the melting temperature. The thickness of this film is preferably as thin as possible, and is usually 0.5 to 1. The amount of salmon r/mice is used.

In addition, this film layer may be prepared in advance in the form of a film, or it may be prepared in the form of a solution using an organic solvent and applied to the surface of the thermosetting resin layer or the curing agent layer. If the film layer is provided by volatilizing the solvent, the film layer can be made thinner, which is advantageous. In the present invention, the thermoplastic resin fiber base material or film has a softening point or melting temperature similar to or lower than that of the thermosetting resin layer and the curing agent layer, and has good retention or compatibility with both. A material that is soluble and has excellent adhesiveness to the surface to be sealed is used.

For example, vinyl chloride, ethylene ethyl acrylate, ethylene vinyl acetate, nylon, etc. are used depending on the thermosetting resin, the material of the curing agent, and the melting temperature. It is also possible to use polyethylene. It is preferable to use this thermoplastic resin fiber base material or film in the form of a non-woven fabric rather than in the form of a woven fabric or film to achieve homogeneous dispersion in the thermosetting resin or curing agent in which it is embedded. It is advantageous in The thickness of this thermoplastic resin fiber base film varies depending on its material, amount of thermosetting resin, etc., but is usually 0.05 to 0.5 mm, preferably 0.1 mm.
~0.3 side. As shown in FIGS. 1 and 2, the thermosetting sealing material according to the present invention has a thermosetting resin layer a and a curing agent layer b in at least one layer. , containing a thermoplastic fiber base material or film c, or as shown in Figures 3 and 4, either the thermosetting resin layer a or the curing agent layer b is made into two layers, Either layer contains a thermoplastic fiber base material or film c. In FIGS. 1 to 4, d is a hot-melt contact prevention film layer. Examples of the present invention will be described below.

Example 1 A 50% solution was prepared by dissolving bisphenolepoxy resin manufactured by Shell Chemical Co., Ltd., trade name Epon #1001 in an equal amount of methyl ethyl ketone-toluene mixed solvent, and this was
Manufactured by Daifuku Paper Co., Ltd., 100% acrylic nonwoven fabric, product name Ap7
3-200 was impregnated on both sides and dried at 80 pm for 2 hours to obtain a thermosetting resin sheet containing a thermoplastic fiber base material with a resin adhesion amount of 350 pm.

A 10% mineral spirit solution of alkylphenol resin manufactured by Dainippon Ink Co., Ltd., trade name TD-773, was applied to both sides of this sheet, and this was dried at 7500 for 1q minutes.
A heat-melting type contact prevention layer with a coating weight of 5 coats/day was provided. Furthermore,
Manufactured by Shikoku Kasei Co., Ltd., condecyl imidazole, product name CM
A 20% solution of methanol was applied onto each contact prevention layer, dried at 70:00 for 10 minutes, and a hardening agent layer with a coating weight of 10/force was provided to obtain a thermosetting sealing sheet. .

When this Example product was inserted into a pin, this pin was inserted into a pin insertion hole of a plate, and heated at 12,000 ℃ for 20 minutes, the pin could be reliably sealed and fixed.

Example 2 A 70% solution of methyl ethyl ketone containing 10 parts of acrylic unsaturated material (product name: Lipoxy R-6 female, manufactured by Showa Kobunshi Co., Ltd.) and 4 parts of lauroyl peroxide was mixed with a polyethylene nonwoven fabric (product name, manufactured by DuPont). The mixture was coated on one side of Tyvek and dried at 70 qo for 15 minutes to obtain a thermosetting resin sheet containing a thermoplastic fiber base material with a resin adhesion amount of 80 ml.

One side of this sheet was coated with ethylene vinyl acetate copolymer manufactured by Mitsui Polychemical Co., Ltd., product name Elvax-210.
A 0% toluene solution was applied and dried at 65°C for 10 minutes to provide a heat-melting type contact prevention layer with a coating weight of 2°C. Next, a 50% methanol solution of methanol-soluble nylon manufactured by Toray Industries, Inc. (trade name: Amilan CM-400110) and 0.2 parts of NN' dimethylaniline was applied to the surface of the contact prevention layer, and dried at 6000 for 15 minutes. Adhesion amount 50
Evening: A thermosetting sheet was obtained by providing that curing agent layer.

Using this Example product, the pins were sealed in the same manner as in Example 1 by heating at 100q0 for 10 minutes, and the sealing was reliable.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are explanatory drawings showing various examples of the sealing material according to the present invention. In the figure, a is a curable resin layer, b is a curing agent layer, c is a thermoplastic resin fiber base material or film, and d is a heat-melting contact prevention film layer. Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 Consisting of a thermosetting resin layer, a curing agent layer, and a heat-melting contact prevention film layer interposed between the thermosetting resin layer and the curing agent layer, at least the thermosetting resin layer and the curing agent layer. A thermoplastic resin fiber base material or film is present in one layer, and this base material or film and the heat-melting contact prevention film layer have substantially the same softening point or melting temperature or a lower softening point as the other two layers. or a thermosetting sealing material characterized by having a melting temperature.